Commit Graph

922 Commits

Author SHA1 Message Date
Vineet Gupta
d0e73e2ac6 ARC: Revert "ARC: mm: IOC: Don't enable IOC by default"
The programming model has been fixed with prev patches so re-enable it
by default

This reverts commit 23cb1f6440.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-01-18 19:21:06 -08:00
Vineet Gupta
76894a72a0 ARC: mm: split arc_cache_init to allow __init reaping of bulk
arc_cache_init() is called for each core so can't be tagged __init.
However bulk of it is only executed by master core and thus is candidate
for __init reaping.

So split it up to allow that.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-01-18 19:21:02 -08:00
Vineet Gupta
e497c8e52a ARCv2: IOC: Use actual memory size to setup aperture size
vs. fixed 512M before.

But this still assumes that all of memory is under IOC which may not be
true for the SoC. Improve that later when this becomes a real issue, by
specifying this from DT.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-01-18 14:52:43 -08:00
Vineet Gupta
8c47f83ba4 ARCv2: IOC: Adhere to progamming model guidelines to avoid DMA corruption
On AXS103 release bitfiles, DMA data corruptions were seen because IOC
setup was not following the recommended way in documentation.

Flipping IOC on when caches are enabled or coherency transactions are in
flight, might cause some of the memory operations to not observe
coherency as expected.

So strictly follow the programming model recommendations as documented
in comment header above arc_ioc_setup()

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-01-18 14:48:33 -08:00
Vineet Gupta
d4911cdd32 ARCv2: IOC: refactor the IOC and SLC operations into own functions
- Move IOC setup into arc_ioc_setup()
 - Move SLC disabling into arc_slc_disable()

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-01-18 14:35:10 -08:00
Vineet Gupta
eb1357d942 ARC: module: Fix !CONFIG_ARC_DW2_UNWIND builds
commit d65283f7b6 added mod->arch.secstr under
CONFIG_ARC_DW2_UNWIND, but used it unconditionally which broke builds
when the option was disabled. Fix that by adjusting the #ifdef guard.

And while at it add a missing guard (for unwinder) in module.c as well

Reported-by: Waldemar Brodkorb <wbx@openadk.org>
Cc: stable@vger.kernel.org    #4.9
Fixes: d65283f7b6 ("ARC: module: elide loop to save reference to .eh_frame")
Tested-by: Anton Kolesov <akolesov@synopsys.com>
Reviewed-by: Alexey Brodkin <abrodkin@synopsys.com>
[abrodkin: provided fixlet to Kconfig per failure in allnoconfig build]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-01-18 11:17:44 -08:00
Vineet Gupta
ecd43afdbe ARCv2: save r30 on kernel entry as gcc uses it for code-gen
This is not exposed to userspace debugers yet, which can be done
independently as a seperate patch !

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-01-10 11:51:33 -08:00
Yuriy Kolerov
e51d5d02f6 ARCv2: IRQ: Call entry/exit functions for chained handlers in MCIP
It is necessary to call entry/exit functions for parent interrupt
controllers for proper masking/unmasking of interrupt lines.

Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-01-04 17:12:11 -08:00
Yuriy Kolerov
2163266c27 ARC: IRQ: Use hwirq instead of virq in mask/unmask
It is necessary to use hwirq instead of virq when you communicate
with an interrupt controller since there is no guaranty that virq
numbers match hwirq numbers.

Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-01-04 17:12:10 -08:00
Vineet Gupta
fa84d7310d ARC: mmu: clarify the MMUv3 programming model
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2017-01-04 17:12:09 -08:00
Linus Torvalds
42e0372c0e Merge tag 'arc-4.10-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Pull more ARC updates from Vineet Gupta:

 - Fix for aliasing VIPT dcache in old ARC700 cores

 - micro-optimization in ARC700 ProtV handler

 - Enable SG_CHAIN  [Vladimir]

 - ARC HS38 core intc default to prio 1

* tag 'arc-4.10-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: mm: arc700: Don't assume 2 colours for aliasing VIPT dcache
  ARC: mm: No need to save cache version in @cpuinfo
  ARC: enable SG chaining
  ARCv2: intc: default all interrupts to priority 1
  ARCv2: entry: document intr disable in hard isr
  ARC: ARCompact entry: elide re-reading ECR in ProtV handler
2016-12-23 10:22:47 -08:00
Vineet Gupta
08fe007968 ARC: mm: arc700: Don't assume 2 colours for aliasing VIPT dcache
An ARC700 customer reported linux boot crashes when upgrading to bigger
L1 dcache (64K from 32K). Turns out they had an aliasing VIPT config and
current code only assumed 2 colours, while theirs had 4. So default to 4
colours and complain if there are fewer. Ideally this needs to be a
Kconfig option, but heck that's too much of hassle for a single user.

Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-12-19 11:55:17 -08:00
Vineet Gupta
f64915be2d ARC: mm: No need to save cache version in @cpuinfo
Historical MMU revisions have been paired with Cache revision updates
which are captured in MMU and Cache Build Configuration Registers respectively.

This was used in boot code to check for configurations mismatches,
speically in simulations (such as running with non existent caches,
non pairing MMU and Cache version etc). This can instead be inferred
from other cache params such as line size. So remove @ver from post
processed @cpuinfo which could be used later to save soem other
interesting info.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-12-19 11:54:41 -08:00
Vladimir Kondratiev
983eeba7d2 ARC: enable SG chaining
Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev@intel.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-12-18 18:45:32 -08:00
Linus Torvalds
d25b6af91e Merge tag 'arc-4.10-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Pull ARC updates from Vineet Gupta:
 "These are mostly timer/clocksource driver updates which were
  Reviewed/Acked by Daniel but had to be merged via ARC tree due to
  dependencies.

  I will follow up with another pull request with actual ARC changes
  early next week !

  Summary:

   - Moving ARC timer driver into drivers/clocksource

   - EZChip timer driver updates [Noam]

   - ARC AXS103 and HAPS platform updates [Alexey]"

* tag 'arc-4.10-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: axs10x: really enable ARC PGU
  ARC: rename Zebu platform support to HAPS
  clocksource: nps: avoid maybe-uninitialized warning
  clocksource: Add clockevent support to NPS400 driver
  clocksource: update "fn" at CLOCKSOURCE_OF_DECLARE() of nps400 timer
  soc: Support for NPS HW scheduling
  clocksource: import ARC timer driver
  ARC: breakout timer include code into separate header ...
  ARC: move mcip.h into include/soc and adjust the includes
  ARC: breakout aux handling into a separate header
  ARC: time: move time_init() out of the driver
  ARC: timer: gfrc, rtc: build under same option (64-bit timers)
  ARC: timer: gfrc, rtc: Read BCR to detect whether hardware exists ...
  ARC: timer: gfrc, rtc: deuglify big endian code
2016-12-15 14:15:17 -08:00
Linus Torvalds
e3842cbfe0 Merge tag 'dmaengine-4.10-rc1' of git://git.infradead.org/users/vkoul/slave-dma
Pull dmaengine updates from Vinod Koul:
 "Fairly routine update this time around with all changes specific to
  drivers:

   - New driver for STMicroelectronics FDMA
   - Memory-to-memory transfers on dw dmac
   - Support for slave maps on pl08x devices
   - Bunch of driver fixes to use dma_pool_zalloc
   - Bunch of compile and warning fixes spread across drivers"

[ The ST FDMA driver already came in earlier through the remoteproc tree ]

* tag 'dmaengine-4.10-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (68 commits)
  dmaengine: sirf-dma: remove unused ‘sdesc’
  dmaengine: pl330: remove unused ‘regs’
  dmaengine: s3c24xx: remove unused ‘cdata’
  dmaengine: stm32-dma: remove unused ‘src_addr’
  dmaengine: stm32-dma: remove unused ‘dst_addr’
  dmaengine: stm32-dma: remove unused ‘sfcr’
  dmaengine: pch_dma: remove unused ‘cookie’
  dmaengine: mic_x100_dma: remove unused ‘data’
  dmaengine: img-mdc: remove unused ‘prev_phys’
  dmaengine: usb-dmac: remove unused ‘uchan’
  dmaengine: ioat: remove unused ‘res’
  dmaengine: ioat: remove unused ‘ioat_dma’
  dmaengine: ioat: remove unused ‘is_raid_device’
  dmaengine: pl330: do not generate unaligned access
  dmaengine: k3dma: move to dma_pool_zalloc
  dmaengine: at_hdmac: move to dma_pool_zalloc
  dmaengine: at_xdmac: don't restore unsaved status
  dmaengine: ioat: set error code on failures
  dmaengine: ioat: set error code on failures
  dmaengine: DW DMAC: add multi-block property to device tree
  ...
2016-12-14 20:42:45 -08:00
Alexander Duyck
8a3385d2d4 arch/arc: add option to skip sync on DMA mapping
Patch series "Add support for DMA writable pages being writable by the
network stack", v3.

The first 19 patches in the set add support for the DMA attribute
DMA_ATTR_SKIP_CPU_SYNC on multiple platforms/architectures.  This is
needed so that we can flag the calls to dma_map/unmap_page so that we do
not invalidate cache lines that do not currently belong to the device.
Instead we have to take care of this in the driver via a call to
sync_single_range_for_cpu prior to freeing the Rx page.

Patch 20 adds support for dma_map_page_attrs and dma_unmap_page_attrs so
that we can unmap and map a page using the DMA_ATTR_SKIP_CPU_SYNC
attribute.

Patch 21 adds support for freeing a page that has multiple references
being held by a single caller.  This way we can free page fragments that
were allocated by a given driver.

The last 2 patches use these updates in the igb driver, and lay the
groundwork to allow for us to reimplement the use of build_skb.

This patch (of 23):

This change allows us to pass DMA_ATTR_SKIP_CPU_SYNC which allows us to
avoid invoking cache line invalidation if the driver will just handle it
later via a sync_for_cpu or sync_for_device call.

Link: http://lkml.kernel.org/r/20161110113419.76501.38491.stgit@ahduyck-blue-test.jf.intel.com
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-14 16:04:07 -08:00
Vineet Gupta
107177b14d ARCv2: intc: default all interrupts to priority 1
ARC HS Cores support configurable multiple interrupt priorities of upto
16 levels. In commit dec2b2849c ("ARCv2: intc: Allow interruption by
lowest priority interrupt") we switched to 15 which seems a bit
excessive given that there would be rare hardware implementing so many
preemption levels AND running Linux. It would seem that 2 levels will be
more common so switch to 1 as the default priority level. This will be
the "lower" priority level saving 0 for implementing NMI style support.

This scheme also works in systems with more than 2 prioity levels as
well.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-12-14 09:23:46 -08:00
Vineet Gupta
78833e79d5 ARCv2: entry: document intr disable in hard isr
And while at it - use the proper assembler macro which includes the
optional irq tracing already - de-uglify'ing the code a bit

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-12-14 09:23:45 -08:00
Vineet Gupta
f5f3bde4f6 ARC: ARCompact entry: elide re-reading ECR in ProtV handler
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-12-13 13:16:11 -08:00
Ingo Molnar
6f38751510 Merge branch 'linus' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-11 13:07:13 +01:00
Alexey Brodkin
7badf6fefc ARC: axs10x: really enable ARC PGU
Up until now we had ARC PGU not enabled in axs10x defconfigs trying
to not bloat kernel image again with yet another drivers and subsystems.

This change configures ARC PGU (as well as DRM bits it depends on)
to be built as a module and so those who need LCD screen to work on
axs10x may bundle built .ko files in their target's file-system with
help of the following command on host:
------------->8-------------
make INSTALL_MOD_PATH=_path_to_target_fs_ modules_install
------------->8-------------

and later on target with commands as simple as:
------------->8-------------
modprobe adv7511.ko
modprobe arcpgu.ko
------------->8-------------
get LCD working.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-30 11:54:25 -08:00
Vineet Gupta
4988cc5635 ARC: rename Zebu platform support to HAPS
There are more ARC Linux HAPS users than Zebu ones.

Same kernel would work fine on both, even with embedded DT, assuming the FPGA
bitfile configuration is same

Suggested-by: Francois Bedard <fbedard@ynopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-30 11:54:25 -08:00
Noam Camus
09dcd1958b soc: Support for NPS HW scheduling
This new header file is for NPS400 SoC (part of ARC architecture).
The header file includes macros for save/restore of HW scheduling.
The control of HW scheduling is achieved by writing core registers.
This code was moved from arc/plat-eznps so it can be used
from drivers/clocksource/, available only for CONFIG_EZNPS_MTM_EXT.

Signed-off-by: Noam Camus <noamca@mellanox.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2016-11-30 11:54:25 -08:00
Vineet Gupta
c4c9a040ec clocksource: import ARC timer driver
This adds support for

 - CONFIG_ARC_TIMERS : legacy 32-bit TIMER0 and TIMER1 which count UP
   from @CNT to @LIMIT, before optionally triggering an interrupt.
   These are programmed using ARC auxiliary register interface.
   These are present in all ARC cores (ARC700 and ARC HS38)
   TIMER0 serves as clockevent for all ARC linux builds.
   TIMER1 is used for clocksource in arc700 builds.

 - CONFIG_ARC_TIMERS_64BIT: 64-bit counters, RTC and GFRC found in
   ARC HS38 cores. These are independnet IP blocks with different
   programming model respectively.

Link: http://lkml.kernel.org/r/20161111231132.GA4186@mai
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-30 11:54:25 -08:00
Vineet Gupta
b26c2e3823 ARC: breakout timer include code into separate header ...
... which allows for use in drivers/clocksource later

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-30 11:54:25 -08:00
Vineet Gupta
2d7f5c48c0 ARC: move mcip.h into include/soc and adjust the includes
Also remove the dependency on ARCv2, to increase compile coverage for
!ARCV2 builds

Acked-by: Daniel Lezcano <daniel.lezcnao@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-30 11:54:25 -08:00
Vineet Gupta
c33a605dd6 ARC: breakout aux handling into a separate header
ARC timers use aux registers for programming and this paves way for
moving ARC timer drivers into drivers/clocksource

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-30 11:54:25 -08:00
Vineet Gupta
92b0331403 ARC: time: move time_init() out of the driver
to allow future git mv of the driver into drivers/clocksource

Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-30 11:54:25 -08:00
Vineet Gupta
044214200b ARC: timer: gfrc, rtc: build under same option (64-bit timers)
The original distinction was done as they were developed at different
times and primarily because they are specific to UP (RTC) and SMP (GFRC).

But given that driver handles that at runtime, (i.e. not allowing
RTC as clocksource in SMP), we can simplify things a bit.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-30 11:54:25 -08:00
Vineet Gupta
ec7cb87bf9 ARC: timer: gfrc, rtc: Read BCR to detect whether hardware exists ...
... don't rely on cpuinfo populated in arc boot code. This paves way for
moving this code in drivers/clocksource/

And while at it, convert the WARN() to pr_warn() as sugested by Daniel

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-30 11:54:25 -08:00
Vineet Gupta
2cd690ea6d ARC: timer: gfrc, rtc: deuglify big endian code
A standard "C" shift will be handled appropriately by the compiler
depending on the endian for the build. So we don't need the
explicit distinction in code

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-30 11:54:25 -08:00
Eugeniy Paltsev
bd2c6636cc dmaengine: DW DMAC: add multi-block property to device tree
Several versions of DW DMAC have multi block transfers hardware
support. Hardware support of multi block transfers is disabled
by default if we use DT to configure DMAC and software emulation
of multi block transfers used instead.
Add multi-block property, so it is possible to enable hardware
multi block transfers (if present) via DT.

Switch from per device is_nollp variable to multi_block array
to be able enable/disable multi block transfers separately per
channel.

Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-11-30 08:57:50 +05:30
Yuriy Kolerov
6a8b2ca702 ARC: mm: PAE40: Fix crash at munmap
commit 1c3c909303 broke PAE40. Macro pfn_pte(pfn, prot) creates paddr
from pfn, but the page shift was getting truncated to 32 bits since we lost
the proper cast to 64 bits (for PAE400

Instead of reverting that commit, use a better helper which is 32/64 bits
safe just like ARM implementation.

Fixes: 1c3c909303 ("ARC: mm: fix build breakage with STRICT_MM_TYPECHECKS")
Cc: <stable@vger.kernel.org>   #4.4+
Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
[vgupta: massaged changelog]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-29 09:12:08 -08:00
Vineet Gupta
23cb1f6440 ARC: mm: IOC: Don't enable IOC by default
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-28 09:18:36 -08:00
Vineet Gupta
3c7c7a2fc8 ARC: Don't use "+l" inline asm constraint
Apparenty this is coming in the way of gcc fix which inhibits the usage
of LP_COUNT as a gpr.

Cc: stable@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-28 09:17:32 -08:00
Ingo Molnar
02cb689b2c Merge branch 'linus' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-22 12:37:38 +01:00
Christian Borntraeger
6d0d287891 locking/core: Provide common cpu_relax_yield() definition
No need to duplicate the same define everywhere. Since
the only user is stop-machine and the only provider is
s390, we can use a default implementation of cpu_relax_yield()
in sched.h.

Suggested-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Noam Camus <noamc@ezchip.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-s390 <linux-s390@vger.kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1479298985-191589-1-git-send-email-borntraeger@de.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-17 08:17:36 +01:00
Christian Borntraeger
5bd0b85ba8 locking/core, arch: Remove cpu_relax_lowlatency()
As there are no users left, we can remove cpu_relax_lowlatency()
implementations from every architecture.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Noam Camus <noamc@ezchip.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Cc: <linux-arch@vger.kernel.org>
Link: http://lkml.kernel.org/r/1477386195-32736-6-git-send-email-borntraeger@de.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-16 10:15:11 +01:00
Christian Borntraeger
79ab11cdb9 locking/core: Introduce cpu_relax_yield()
For spinning loops people do often use barrier() or cpu_relax().
For most architectures cpu_relax and barrier are the same, but on
some architectures cpu_relax can add some latency.
For example on power,sparc64 and arc, cpu_relax can shift the CPU
towards other hardware threads in an SMT environment.
On s390 cpu_relax does even more, it uses an hypercall to the
hypervisor to give up the timeslice.
In contrast to the SMT yielding this can result in larger latencies.
In some places this latency is unwanted, so another variant
"cpu_relax_lowlatency" was introduced. Before this is used in more
and more places, lets revert the logic and provide a cpu_relax_yield
that can be called in places where yielding is more important than
latency. By default this is the same as cpu_relax on all architectures.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Noam Camus <noamc@ezchip.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1477386195-32736-2-git-send-email-borntraeger@de.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-16 10:15:09 +01:00
Linus Torvalds
e6251f009b Merge tag 'arc-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Pull ARC fixes from Vineet Gupta:

 - mmap handler for dma ops as generic handler no longer works for us
   [Alexey]

 - Fixes for EZChip platform [Noam]

 - Fix RTC clocksource driver build issue

 - ARC IRQ handling fixes [Yuriy]

 - Revert a recent makefile change which doesn't go well with oldish
   tools out in the wild

* tag 'arc-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARCv2: MCIP: Use IDU_M_DISTRI_DEST mode if there is only 1 destination core
  ARC: IRQ: Do not use hwirq as virq and vice versa
  ARC: [plat-eznps] set default baud for early console
  ARC: [plat-eznps] remove IPI clear from SMP operations
  Revert "ARC: build: retire old toggles"
  ARC: timer: rtc: implement read loop in "C" vs. inline asm
  ARC: change return value of userspace cmpxchg assist syscall
  arc: Implement arch-specific dma_map_ops.mmap
  ARC: [SMP] avoid overriding present cpumask
  ARC: Enable PERF_EVENTS in nSIM driven platforms
2016-11-11 16:51:50 -08:00
Arnd Bergmann
a76bcf557e Kbuild: enable -Wmaybe-uninitialized warning for "make W=1"
Traditionally, we have always had warnings about uninitialized variables
enabled, as this is part of -Wall, and generally a good idea [1], but it
also always produced false positives, mainly because this is a variation
of the halting problem and provably impossible to get right in all cases
[2].

Various people have identified cases that are particularly bad for false
positives, and in commit e74fc973b6 ("Turn off -Wmaybe-uninitialized
when building with -Os"), I turned off the warning for any build that
was done with CC_OPTIMIZE_FOR_SIZE.  This drastically reduced the number
of false positive warnings in the default build but unfortunately had
the side effect of turning the warning off completely in 'allmodconfig'
builds, which in turn led to a lot of warnings (both actual bugs, and
remaining false positives) to go in unnoticed.

With commit 877417e6ff ("Kbuild: change CC_OPTIMIZE_FOR_SIZE
definition") enabled the warning again for allmodconfig builds in v4.7
and in v4.8-rc1, I had finally managed to address all warnings I get in
an ARM allmodconfig build and most other maybe-uninitialized warnings
for ARM randconfig builds.

However, commit 6e8d666e92 ("Disable "maybe-uninitialized" warning
globally") was merged at the same time and disabled it completely for
all configurations, because of false-positive warnings on x86 that I had
not addressed until then.  This caused a lot of actual bugs to get
merged into mainline, and I sent several dozen patches for these during
the v4.9 development cycle.  Most of these are actual bugs, some are for
correct code that is safe because it is only called under external
constraints that make it impossible to run into the case that gcc sees,
and in a few cases gcc is just stupid and finds something that can
obviously never happen.

I have now done a few thousand randconfig builds on x86 and collected
all patches that I needed to address every single warning I got (I can
provide the combined patch for the other warnings if anyone is
interested), so I hope we can get the warning back and let people catch
the actual bugs earlier.

This reverts the change to disable the warning completely and for now
brings it back at the "make W=1" level, so we can get it merged into
mainline without introducing false positives.  A follow-up patch enables
it on all levels unless some configuration option turns it off because
of false-positives.

Link: https://rusty.ozlabs.org/?p=232 [1]
Link: https://gcc.gnu.org/wiki/Better_Uninitialized_Warnings [2]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-11 08:45:08 -08:00
Ingo Molnar
4c8ee71620 Merge branch 'linus' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-11 08:25:07 +01:00
Yuriy Kolerov
0a0a047def ARCv2: MCIP: Use IDU_M_DISTRI_DEST mode if there is only 1 destination core
ARC linux uses 2 distribution modes for common interrupts: round robin
mode (IDU_M_DISTRI_RR) and a simple destination mode (IDU_M_DISTRI_DEST).
The first one is used when more than 1 cores may handle a common interrupt
and the second one is used when only 1 core may handle a common interrupt.

However idu_irq_set_affinity() always sets IDU_M_DISTRI_RR for all affinity
values. But there is no sense in setting of such mode if only 1 core must
handle a common interrupt.

Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-08 12:22:52 -08:00
Yuriy Kolerov
34e71e4cbb ARC: IRQ: Do not use hwirq as virq and vice versa
This came up when reviewing code to address missing IRQ affinity
setting in AXS103 platform and/or implementing hierarchical IRQ domains

- smp_ipi_irq_setup() callers pass hwirq but in turn calls
  request_percpu_irq() which expects a linux virq. So invoke
  irq_find_mapping() to do the conversion
  (also explicitify this in code by renaming the args appropriately)

- idu_of_init()/idu_cascade_isr() were similarly using linux virq where
  hwirq is expected, so do the conversion using irqd_to_hwirq() helper

Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
[vgupta: made changelog a bit concise a bit]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-08 12:05:10 -08:00
Noam Camus
19dbc76228 ARC: [plat-eznps] set default baud for early console
For CONFIG_SERIAL_EARLYCON we need 800MHz for NPS SoC
The early console driver uses BASE_BAUD and not using dtb.

The default of 50MHz is NOT good for NPS SoC.

Signed-off-by: Noam Camus <noamca@mellanox.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-08 09:39:37 -08:00
Noam Camus
66619433d0 ARC: [plat-eznps] remove IPI clear from SMP operations
Today we register to plat_smp_ops.clear() method which actually
is acking the IPI.
However this is already taking care by our irqchip driver specifically
by the irq_chip.irq_eoi() method.
This is perfect timing where it should be done and no special handling
is needed at plat_smp_ops.clear().

Signed-off-by: Noam Camus <noamca@mellanox.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-08 09:25:18 -08:00
Vineet Gupta
76a0840474 Revert "ARC: build: retire old toggles"
This has caused a bunch of build failures at a few sites, with GNU
2015.12 and older as the assembler seems to need -mlock to be able to
grok llock/scond instructions for ARC700 builds.
different places since the
older tools still seem to release
of tools which most people are using seem to trip with the -mlock flag
not being passed.

This reverts commit c300547588.
2016-11-08 09:23:52 -08:00
Vineet Gupta
922cc17199 ARC: timer: rtc: implement read loop in "C" vs. inline asm
The current code doesn't even compile as somehow the inline assembly
can't see the register names defined as ARC_RTC_*
I'm pretty sure It worked when I first got it merged, but the tools were
definitely different then.

So better to write this in "C" anyways.

CC: stable@vger.kernel.org	#4.2+
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-07 11:19:44 -08:00
Vineet Gupta
e6e335bf3a ARC: change return value of userspace cmpxchg assist syscall
The original syscall only used to return errno to indicate if cmpxchg
succeeded. It was not returning the "previous" value which typical cmpxchg
callers are interested in to build their slowpaths or retry loops.
Given user preemption in syscall return path etc, it is not wise to
check this in userspace afterwards, but should be what kernel actually
observed in the syscall.

So change the syscall interface to always return the previous value and
additionally set Z flag to indicate whether operation succeeded or not
(just like ARM implementation when they used to have this syscall)
The flag approach avoids having to put_user errno which is nice given
the use case for this syscall cares mostly about the "previous" value.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-11-07 11:01:12 -08:00